关附甲素对豚鼠乳头肌动作电位最大除极速度的频率依赖性抑制作用

应用标准微电极技术，研究了关附甲素对豚鼠右心室乳头肌动作电位最大除极速率(V_max)的频率依赖性抑制作用(RDB)，并与美西律，奎尼丁，劳卡尼进行了比较. 在相同刺激间隔(300 ms)，产生50%左右RDB的药物浓度下，美西律的RDB开始最快，其第2个V_max所产生的抑制已占RDB的64%，奎尼丁，劳卡尼和关附甲素的RDB开始速率常数分别为每个动作电位0.165, 0.076和0.136. 美西律，奎尼丁，劳卡尼和关附甲素产生RDB的恢复时间常数分别为1.4, 9.0, 18.2和44.0 s，而且它们的恢复时间常数是不依赖于药物浓度而变化的，结果提示，关附甲素是一个慢动力学钠通道阻滞剂.     

Primary spinal paragangliomas: a clinicopathological and immunohistochemical study of 30 cases

Aims: Extra-adrenal paragliomas are neoplasms which have been the subject of much debate regarding parameters to establish their biological behaviour. This study describes the clinicopathological and immunohistochemical features of 30 cases of spinal paragliomas. Methods and results: There were 15 male and 15 female patients. The median age at diagnosis was 46 years (range 20–74 years). Fourteen patients presented with back pain, two with numbness of the lower extremities, one with difficulty in walking and one with spinal cord compression. Nineteen tumours were located in the lumbar region, six in the cauda equina, two in the filum terminale, two in the thoracic region and one in the cervical region. All patients underwent gross total excision. The size of the tumours ranged from 10 to 50 mm. Histologically, 18 neoplasms showed alveolar (Zellballen) pattern, seven a spindle component, two eosinophilic granular cells suggestive of oncocytic metaplasia, two melanin pigment and one ganglion cells. Positive immunohistochemical results include: neuron-specific enolase 23/23 (100%), synaptophysin 21/23 (91%), S100 protein 22/23 (95%, sustentacular cells), leu-enkephalin 11/23 (47%), somatostatin 8/23 (34%), focal glial fibrillary acidic protein 7/23 (30%), focal keratin 5/23 (21%), neurofilament proteins 3/23 (13%) and adrenocorticotrophic hormine (ACTH) 1/23 (4%). Follow-up information obtained in 20 patients show 17 patients alive over a period of 6–216 months. One patient had bone metastases. Two patients died of unrelated causes, including one of congestive heart failure and one of myocardial infarction. Conclusions: In our experience, spinal paragangliomas behave as slow-growing tumours susceptible to potential cure by total excision. We agree with the current World Health Organization (WHO) classification as grade I tumours. Less than 1% may be locally aggressive. Spinal paragangliomas immunoreact not only for conventional neuroendocrine markers but also for peptides including somatostatin and ACTH and focally for the epithelial marker keratin.     

Shaping ability of the M4 handpiece and Safety Hedstrom Files in simulated root canals

The aim of this study was to assess the shaping ability of the M4 reciprocating handpiece and Safety Hedstrom files in simulated canals. A total of 40 simulated canals of various angles and positions of curvature were prepared with an M4 handpiece using Safety Hedstrom files oriented with the ground, flattened surface towards the inner aspect of the curve. A standard regimen was adopted throughout. Pre- and post-operative longitudinal images of the canals were taken with a video camera and stored and manipulated in a computer with image analysis software. The presence of canal aberrations and the amount and location of resin material removed as a result of preparation were determined from composite images of superimposed pre- and post-operative views. Preparation time varied significantly (P<0.001) between the canal types; overall, 20° canals were prepared more quickly than 40° canals. Zips and elbows were observed in 16 out of the 40 canals with most (11) being created in 40° specimens. Ledges were found in 19 canals and perforations in only 1. There were no significant differences between canal shapes for these aberrations. Excessive removal of material from the inner aspect of the canal at the curve to create a danger zone was found in 20 canals, but only in those with 40° curves. Significant differences in total canal width between the canal types were seen at the zips (P<0.05), elbows (P<0.05) and danger zones (P<0.001). Transportation at the danger zones varied significantly (P<0.001) between canal types. Under the conditions of this study, the M4 handpiece and Safety Hedstrom files created hour-glass preparations in a substantial proportion of canals. In reality, the Safety Hedstrom file with its one flattened surface was ineffective at reducing removal of material along the inner aspect of canal curves in severely curved specimens and clearly has the potential to create strip perforations in teeth.     

The prevalence of autonomic neuropathy in the primary glaucomas

The results of systemic autonomic nerve function studies in patients with closed-angle glaucoma and ocular hypertension are reviewed. Autonomic neuropathy has been demonstrated in 58% of patients with closed-angle glaucoma and 42% of ocular hypertensive subjects, with significantly increased prevalence in ocular hypertensives with narrow iridocorneal angles. The implications are discussed, with particular reference to the pathogenesis of raised intraocular pressure.     

Comparative bactericidal exposures for selected oral bacteria using carbon dioxide laser radiation

Although relatively high CO2 laser energies have been shown to sterilize root canals, the response of several bacterial strains to decreasing exposures of CO2 laser energy remains unknown. Freshly grown bacterial cells were irradiated on glass microscope coverslips. A comparison of equivalent energy exposures with differing parameters was made on the bacterial viability. No statistically significant difference was found in the energy required to kill closely related bacterial species. However, the energy density required to kill greater than 99.5% of the bacteria is less than 200 J/cm2, much less than that shown to sterilize in a previous study.     

颈静脉窝的应用解剖学研究

本文通过200例成人颅颈静脉窝的观察与测量,对颈静脉窝的形态、位置及其与颅后窝、面神经管垂直部、鼓环的局部解剖关系进行研究,为临床应用及体质调查提供资料。     

后天性外耳道狭窄的手术治疗

目的探讨后天性外耳道狭窄的手术治疗方法及效果。方法对26例（27耳）外耳道狭窄行外耳道成形术或厢乳突根治鼓室成型术，取大腿内侧自体游离中厚皮片植皮，碘仿纱条压迫并扩张耳道。结果26例病人27耳随访6个月至8年，24耳外耳道宽敞，无再狭窄；3耳出现轻度狭窄，发生率11．1％（3／27），效果满意。结论对后天性外耳道狭窄的治疗可根据狭窄的原因、部位及程度等不同情况采用外耳道成形、游离中厚皮片移植或同时进行乳突根治鼓室成型术等手术治疗，术后局部换药，即能取得较好效果。     

显微内窥镜下治疗腰椎间盘突出症和腰椎管狭窄症

目的探讨显微内窥镜(MED)治疗腰椎间盘突出症和腰椎管狭窄症的临床效果。方法MED下切除增生内聚的关节突、肥厚的黄韧带及突出的椎间盘，彻底解除对硬膜、神经根的压迫。结果随访324例，按中华骨科学脊柱学组腰背痛手术评定标准，优297例，良14例，差13例，疗效优良率达96．0％，结论MED损伤小、恢复快、疗效好。     

Treatment of fecal incontinence by temporary sacral nerve stimulation

Summary BACKGROUND: Sacral nerve stimulation (SNS) is an option for the treatment of fecal incontinence in patients with morphologically intact, but weak external anal sphincter. METHODS: In ten patients a percutaneous test-SNS was performed. Two patients suffered from fecal incontinence after surgery, one patient after incomplete leg palsy after traumatic spine injury and seven patients from idiopathic incontinence. Incontinence score, anorectal manometry and patient diary were performed before and after test-SNS. RESULTS: Intraoperative response (Bellows action) could be achieved in 90% of patients. Test-SNS was successful in 50% of patients. In these patients, resting pressure was increased by 100.1% and squeeze pressure by 84.5%. CONCLUSIONS: SNS is an effective therapy in a subset of patients with fecal incontinence. Fifty percent of patients tested are eligible for implantation of a permanent stimulation device.      

原发性骶骨肿瘤病理及影像学表现

目的:分析原发性骶骨肿瘤的病理学分型及影像学表现特点。方法:48例原发性骶骨肿瘤均经手术病理证实,术前均行常规X线平片、CT和/或MR检查,结合病理回顾分析了其影像学表现。结果:原发性骶骨肿瘤以脊索瘤(21例)最多见,其次是巨细胞瘤(7例)、神经源性肿瘤(6例)、软骨肉瘤(4例)、滑膜肉瘤(3例),囊肿(3例),其它相对少见,包括纤维组织细胞癌1例,尤文氏肉瘤1例,梭形细胞癌1例,节细胞神经瘤1例。影像表现包括软组织肿块、骶孔扩大、瘤灶内钙化、骨嵴形成等不同特点。常见原发骶骨肿瘤常有其特征性影像学表现。结论:原发骶骨肿瘤病理分型相对复杂,影像表现多样化,诊断常需综合不同影像检查手段。